The present invention relates to a pressure control valve as well as a method for making a pressure control valve.
Such a pressure control valve is known in practice, and in particular, is designed for use with a hydraulic servo circuit of an automatic transmission of a motor vehicle, whereby, by means of the pressure control valve, the pressure is adjusted in a servo circuit. Via the fluid pressure, a slide valve or the like can be actuated, which serves for activating a coupling or switching operation. This type of known pressure control valve includes a valve unit extruded from plastic, in which hydraulic channels are formed. A fluid flow flowing between the hydraulic channels can be controlled by means of a valve closing member.
The valve closing member cooperates with a piston or slide valve, which can be actuated by means of an actuator unit arranged coaxially to the valve unit. The actuator unit is formed generally as an electromagnetic actuator unit, which includes a magnetic coil, a magnetic core, or pole core, as well as an armature, which cooperates with the piston or slide valve for actuation of the valve closing member. The valve unit, which is formed as a type of flange, is extruded onto the magnetic core of the actuator unit. The valve unit of the known pressure control valve includes an inner hydraulic area, in which the hydraulic channels are formed. On the inner hydraulic area, a so-called filter cap is attached, which serves as a sealing element and is sealed by means of an adhesive connection.
Manufacturing the adhesive connection, however, is technically expensive. In addition, the adhesive connection has the disadvantage that with dramatic temperature fluctuations in temperature, a sufficient sealability cannot be achieved.
In addition, it is known to make a valve part of a pressure control valve of the above-described type from multiple injection-molded parts, which are connected to one another with an ultra-welding method or also by a laser welding method.
Also, these types of sealing methods are expensive, however, and do not permit an adequate sealability under all conditions of use.